Medications for High Blood Pressure When Breastfeeding
by Anne Eglash MD, IBCLC, FABM
Hey everyone, this weeks’ CQW is geared to toward physicians and other prescribers, but if you work with physicians who write prescriptions for breastfeeding mothers, please pass this along!
Many breastfeeding mothers are on medications to reduce blood pressure. Sometimes the blood pressure medications are needed short term due to pre-eclampsia, but other mothers have a pre-pregnancy history of high blood pressure, and need to stay on medications during pregnancy and postpartum. There are several medication options to treat high blood pressure during lactation, so how is a health care provider to decide?
Dr. Phil Anderson, who writes a column called LactMed Update in Breastfeeding Medicine Journal, addressed this topic in the journal’s March 2018 issue, and makes clear recommendations.
- Diuretics in high doses can decrease the milk supply.
- Among the ACE inhibitors, lisinopril is considered much safer than benazepril and captopril.
- Labetolol, a beta blocker often used for high blood pressure during pregnancy, is safer to continue postpartum for a breastfeeding mother than atenolol.
- The most studied calcium channel blocker during lactation is nifedipine, which has never been shown to cause infant side effects.
- Guanfacine, a blood pressure medication often used to control anger outbursts in children, has been shown to be safe for mothers and infants during lactation.
See the Answer
The good news for nursing mothers with hypertension is that some drugs in currently preferred categories are available with reasonably good safety information during breastfeeding. Diuretics, calcium channel blockers, and ACEIs are first-line drugs that can be used, although it might be best to limit use to drugs with breastfeeding safety information. In patients who do not tolerate an ACEI, ARBs are unlikely to adversely affect nursing infants, although no data are available. Some beta-blockers appear to be acceptable during breastfeeding, but acebutolol and atenolol should be used with caution, especially while nursing a neonate, because of the relatively large amounts excreted into milk and their excretion is predominantly renal. Most other antihypertensive drugs have scant information on use during breastfeeding, but data are sufficient to recommend avoiding clonidine and guanfacine.
It is very common for me to see breastfeeding women in my lactation clinic who are taking medications for high blood pressure, so it is reasonable for all lactation providers to be aware of what high blood pressure medications might be unsafe. The easiest way to know is to look up the medication in the National Library of Medicine’s LactMed, and share this resource with the mother, so that she can show it to her physician or other health care provider. Diuretics in high doses can decrease the milk supply, and Dr. Anderson points out that historically it was used to suppress lactation postpartum. The relatively low doses that we use for high blood pressure or even postpartum cardiomyopathy appear to be safe. However, I suggest observing the milk supply carefully. Among the ACE inhibitors, lisinopril is the least studied medication and for now should be avoided. Labetolol is a beta blocker that is often continued from pregnancy to postpartum. Beta blockers can cause more infant side effects, particularly for premature infants, so it would be reasonable for OB providers to consider shifting the postpartum medication to nifedipine or benazepril rather than using labetolol.
It is reasonable to avoid guanfacine for hypertension during lactation because we have no evidence regarding its effect on infants, and it might have a negative effect on a mother’s prolactin level.